High salinity geothermal brines typically contain up to several hundred parts per million of valuable heavy metals. Because of the large potential flow of geothermal brines from future power plants, metal recovery as a by-product of power production could be significant. Because the heavy metal concentrations are low, a simple and inexpensive process for recovery of heavy metals is desired. Those of skill in the art of course recognize that geothermal brines are just one example of the broad need for methods of heavy metal recovery. Indeed, the need to recover heavy metal ions from dilute aqueous solution is pervasive throughout industry.
Prior art procedures for recovery of heavy metals from solution include precipitation, cyanidization, amalgamation and electrolysis. Unfortunately, such procedures are not always capable of effectively recovering heavy metals from dilute solution, are expensive in terms of energy demand and are frequently quite time consuming.